1. Field of the Invention
The present invention relates to a disposable needle assembly. In particular, the present invention is directed to a micro-injection molded disposable needle assembly having more than one passageway formed therein to permit the simultaneous drawing and administering of fluids through separate passageways. The present invention is also directed to a micro-injection molded disposable assembly having one or more sensors disposed therein for measuring and monitoring one or more desired conditions. The present invention is also directed to a method of forming a disposable needle from an elastomeric material using micro-injection molding.
2. Description of Related Art
U.S. Pat. No. 3,610,226 to Albisser discloses a double lumen cannula instrument for the withdrawal of blood over a prolonged period of time. The instrument includes an inner lumen for withdrawing blood and an outer lumen for introducing an anticoagulent diluent. The relative locations of the openings for the inner and outer lumen permit the mixing of the diluent with the withdrawn blood.
U.S. Pat. No. 5,374,245 to Mahurkar discloses an extruded reinforced multiple-lumen catheter for use in medical applications where fluids must flow simultaneously to and from a patient. Blood is withdrawn for a medical procedure (e.g. dialysis) from the patient through one passageway and returned to the patient through another passageway spaced from the first passageway.
U.S. Pat. No. 5,607,401 to Humphrey discloses augmented polymeric hypodermic needles and lancets. The polymeric needles and lancets are stiffened by augmenting means, which includes a slideable guard or foam insert so that they are able to pierce the skin. Without the augmenting means, it is not possible for the polymeric hypodermic lancet to pierce the skin.
U.S. Pat. No. 5,637,399 to Yoshikawa et al. discloses an extruded synthetic resin needle that is reinforced with combustible fibers. The needle provides a single path administering or withdrawing fluids from a patient.
The prior art described above does not provide for a needle assembly that is capable of prolonged insertion in the patient for both the simultaneous administering of intravenous fluids and the withdrawal of blood without mixing the intravenous fluid with the withdrawn blood. Furthermore, these needle assemblies do not permit the monitoring of the patient without the further insertion of additional needle assemblies or sensors into the patient.
Various devices for internally monitoring a patient are known. U.S. Pat. No. 3,490,441 to Curtis discloses an intra-arterial blood pressure transducer, which includes a needle that is inserted into a blood vessel. The patient""s blood pressure is measured by measuring the deflection of a sheath surrounding the needle. U.S. Pat. No. 4,665,927 discloses a flexible probe formed from a flexible plastic for sensing and measuring temperature. The probe may take the form of a needle that is inserted into the patient. U.S. Pat. No. 5,568,806 to Cheney et al. discloses a transcutaneous sensor insertion set. The insertion set includes a needle assembly having a sensor assembly for insertion into a patient. Upon insertion, the needle assembly may be withdrawn leaving the sensor assembly in place for monitoring the patient. None of these devices permit the simultaneous insertion and/or withdrawal of fluids while monitoring the patient.
U.S. Pat. No. 6,032,059 to Henning et al. discloses a fluid sampling device having a needle assembly for sampling of blood and measuring an analyte of interest within the blood. The device includes an analysis device that determines the required amount of drug to be injected in response to the measured analyte without removal of the device from the patient""s body. In operation, the needle assembly is inserted into a blood vessel of the patient. The blood then flows into the needle to contact the sensor assembly. The blood is analyzed. In response to the analysis, a drug dosage is automatically administered through needle assembly. Although U.S. Pat. No. 6,032,059 discloses a needle assembly connected to a sensor assembly, it does not disclose a needle assembly that permits the simultaneous insertion and withdrawal of fluids from the blood stream while performing a sensing operation. Furthermore, the needle assembly is not designed for prolonged insertion the patient.
It is an object of the present invention to provide a disposable needle assembly that is capable of drawing and administering fluids from a patient.
It is another object of the present invention to provide a disposable needle assembly that is formed from a non-bioreactive material, which permits implantation in a patient for extended periods of time. The present invention eliminates the need for multiple patient injections.
It is another object of the present invention to provide a disposable needle assembly that permits the simultaneous administering of intravenous fluids and the drawing of blood.
It is another object of the present invention to provide a disposable needle assembly that permits the simultaneous administering of intravenous fluids and the drawing of blood without contaminating the blood with the intravenous fluids.
It is yet another object of the present invention to provide a micro-injection molded disposable needle assembly having a plurality of passageways formed therein, wherein at least one of the passageways is provided to withdraw blood from the patient.
It is another object of the present invention to provide a micro-injection molded disposable needle assembly having a plurality of passageways formed therein, wherein at least one of the passageways is provided to administer an intravenous fluid to the patient.
It is another object of the present invention to provide a disposable needle assembly having a plurality of passageways formed therein, wherein at least one of the passageways is provided to withdraw blood from the patient.
It is another object of the present invention to provide a micro-injection molded disposable needle assembly having a plurality of passageways formed therein having a passageway for administering an intravenous fluid and a passageway to withdraw blood from the patient, wherein the passageway for withdrawing blood is capable of being flushed with intravenous fluid at predetermined times.
It is another object of the present invention to provide a disposable needle assembly having at least one sensor located therein for sensing one or more predetermined conditions including but not limited to, chemical agents in the blood stream, blood flow, pressure, and temperature.
It is another object of the present invention to provide a disposable needle assembly having at least one sensor containing at least one polarographic region for sensing chemical agents in the blood stream.
It is another object of the present invention to provide a disposable needle assembly having at least one electroconductive sensor for sensing at least chemical agents in the blood stream and temperature.
It is another object of the present invention to provide a disposable needle assembly having an optical sensor for sensing chemical agents and/or measuring intravenous pressure.
It is another object of the present invention to provide a disposable needle assembly having a flexible diaphragm for use in connection with the measurement of intravenous pressure.
It is another object of the present invention to provide a disposable needle assembly having a flexible diaphragm for use in connection with the measurement of a patient""s pulse.
In response to the foregoing challenges, applicants have developed a needle assembly for use in connection with treating and monitoring a patient. The needle assembly is capable of administering fluids to the patient and also drawing fluids from the patient. The needle is preferably formed by micro-injection molding and is disposable.
The needle assembly includes an elongated needle shaft having a first end and a second end. The needle assembly includes an insertion tip located at a first end of the elongated needle shaft to facilitate insertion of the needle assembly into a vessel of the patient. The insertion tip is preferably integrally formed with the elongated needle shaft.
The needle assembly preferably includes at least one fluid drawing passageway formed in the elongated needle shaft for withdrawing fluid from the patient. Each fluid drawing passageway extends from the second end of the elongated needle shaft to a fluid drawing opening in the elongated needle shaft. The fluid (e.g., blood) within the vessel is withdrawn through the fluid drawing passageway. The drawn fluid may be remotely tested. It is also contemplated that the withdrawn fluid can be medically treated and returned to the vessel.
The needle assembly also preferably includes at least one fluid supply passageway formed in the elongated needle shaft for supplying fluid to the patient. Like the fluid drawing passageway, each fluid supply passageway extends from the second end of the elongated needle shaft to a fluid supply opening in the elongated needle shaft. The fluid introduced into the vessel through the fluid supply passageway may be an intravenous fluid containing nutrients and/or medicaments. It is also contemplated that the fluid supply passageway may return processed blood or plasma to the vessel.
In accordance with the present invention, the fluid supply opening and the fluid drawing opening are spaced from each other along the length of the elongated needle shaft. The spacing of these openings prevents the mixing of the fluid introduced through the fluid supply opening with the fluid removed from the vessel through the fluid drawing opening. It contemplated that one of the openings is located adjacent the insertion tip, while the other of the openings is spaced from the insertion tip.
The needle assembly preferably includes at least one sensor assembly disposed within the elongated needle shaft. The at least one sensor assembly senses at least one predetermined condition of the patient. The at least one sensor assembly may gather the necessary information for the performance of routine lab tests. It is contemplated that the sensor assemblies may be used in connection with Chem 21 testing, and complete blood counts (CBC testing). It is also contemplated that the sensor assemblies may be used in connection with the measurement of alcohol, sodium, potassium, and/or magnesium levels in the bloodstream. The sensor assemblies may also be used in connection with the measurement of internal and external pressures in the venous environment. Furthermore, sensor assemblies may be used to sense and measure body temperature and blood flow. This listing of potential tests and measurement of patient conditions is by no means intended to be exhaustive; rather, numerous other tests and procedures are often performed in connection with the injection of a needle in the patient are considered to be well within the scope of the present invention.
The sensor assembly is preferably disposed within the elongated needle shaft within a sensor passageway formed therein. A sensor is located within the passageway. Numerous sensors are considered to be well within the scope of the present invention including but not limited to optical sensors, temperature sensors, acoustic sensors, pressure sensors (e.g., flexible diaphragms), electrical sensors and chemical sensors. The optical sensor for providing real time visual inspection of the vessel and the blood flow therein. Temperature sensors may be used to measure patient temperature and individual organ temperature. It is also contemplated that the sensor may comprise an electro or chemical sensors. The elongated needle shaft preferably includes at least one recess formed in the outer surface of the shaft. The recesses expose portions of the sensors. It is also contemplated that the above-described sensors may be linked to both visual and audible indicators. For example, an audible indication of blood pressure may be provided in to response to measurement by the sensors.
The elongated needle shaft of the staged needle is preferably formed from an elastomeric material by micro-injection molding. In order to minimize discomfort to the patient, the elastomeric material has a durometer that is slightly greater than the durometer of flesh. The matching of durometer will reduce the uncomfortable irritation of the target vein. This minimization of discomfort permits the needle assembly to be an inserted position in the patient for longer periods of time, which reduces the number of necessary injections. Because this durometer selection, a molded removable core pin used is in connection with the insertion of the needle assembly into vein. The core pin temporarily increases the stability of the needle assembly during the insertion operation. Upon insertion, the core pin is extracted and disposed of, leaving the needle in place.
In accordance with the present invention, the elongated needle shaft is connected to a connector assembly. The connector assembly is secured to the second end of the elongated needle shaft. The connector assembly includes at least one inlet port operatively connected to the at least one fluid supply passageway and at least one outlet port operatively connected to the at least one fluid drawing passageway. Furthermore, the necessary connections for the sensor assemblies are located within the connector assembly. This permits the needle assembly to be connected to a control unit or a monitoring device. The connector assembly may be connected to an attachment assembly for releasably securing the needle assembly to the patient. The attachment assembly may be in the form of the arm band or strap used to secure the needle in place on the patient. The needle assembly is preferably disposed at angle with respect to the attachment assembly.
The present invention is also directed to a method of forming a disposable needle assembly, discussed above. The method includes forming the elongated needle shaft by micro-injection molding. The method further includes forming the connector assembly and securing the connector assembly to the elongated needle shaft. The elongated needle shaft is formed around the at least one sensor assembly. The method further includes forming a removable core pin.
A method of treating a patient is also contemplated in accordance with the present invention. The method includes inserting a disposable needle assembly into a vessel of the patient. The insertion of the disposable needle assembly may also include the insertion of a molded core insert. The moldable core insert is located within one of the passageways of the elongated needle shaft. The core is preferably located within the passageway that extends from the second end to the first end of the shaft adjacent the insertion tip. The moldable core increases the stability of the needle assembly during the insertion process. Upon insertion of the needle assembly within the vessel, the moldable core insert is removed.
The method further includes periodically withdrawing a sample of blood from the patient through a first passageway formed in the elongated needle shaft. The removable of a sample of blood permits the analysis of the blood. Furthermore, a supply an intravenous fluid to the patient may be fed through a second passageway formed in the elongated needle shaft. While this removal of blood and supply of fluid is being performed, the patient can also be monitored through at least one sensor assembly located within the needle assembly. This method is especially advantageous when, for example, a patient is being transferred by emergency vehicle to an emergency room. The paramedics can begin administering necessary IV fluids while monitoring the patient with the insertion of a single needle assembly in the patient. Furthermore, many of the testing operations, discussed above, can be begun or completed before the patient arrives at the emergency room.
Once the testing data is readable, it will be made available to paramedics through a display panel that may be operatively connected to the needle assembly. It is also contemplated that the testing data may be wirelessly transmitted in advance to medical personnel either from an ambulance or critical care unit to a hospital to inform medical staff of the patient""s current physical conditions through different media options.